title: Study of chemical and thermal treatment of kaolinite and its influence on the removal of contaminants from mining effluents.
abstract: The effects of chemical and thermal treatments on the structure of kaolinite were examined, as well as the influence of those changes upon the removal of etheramine, a cationic collector used in the processing of iron ore. The materials were characterized using XRD, XRF, specific surface area (SBET), FTIR, zeta potential and a test for determination of acid sites. The effects of the treatments on the structure of kaolinite were evaluated using chemometric tools developed from principal components analysis algorithms and hierarchical components analysis. The parameters evaluated in the kinetic study of adsorption were contact time, initial concentration of etheramine, quantity of adsorbent and pH. The adsorption of etheramine in the samples subjected to chemical treatments could be explained by a pseudo-second order model, whilst for the sample subjected to thermal treatment, better fit was with the pseudo-first order model. With regard to adsorption isotherms, it was shown that for the three adsorbents used, adsorption followed the Langmuir model. The maximum quantities adsorbed were 27 mg g(-1), 29 mg g(-1) and 59 mg g(-1), respectively, for the samples subjected to acid, thermal and peroxide treatments. The treatment with peroxide was found to be the most suitable for removal of etheramine.
authors.affiliation: Departmento Química, Universidade Federal de Lavras, 37200-000 Lavras, MG, Brazil. priscila.ferreirasa@yahoo.com.br
authors.forename: Priscila F
authors.initials: PF
authors.lastname: de Sales
authors.forename: Zuy M
authors.initials: ZM
authors.lastname: Magriotis
authors.forename: Marco Aurélio de L S
authors.initials: MA
authors.lastname: Rossi
authors.forename: Letícia G
authors.initials: LG
authors.lastname: Tartuci
authors.forename: Rísia M
authors.initials: RM
authors.lastname: Papini
authors.forename: Paulo R M
authors.initials: PR
authors.lastname: Viana
mesh_terms: D000327:Adsorption; D000465:Algorithms; D000588:Amines / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007616:Kaolin / Q000737:chemistry*; D007700:Kinetics; D008906:Mining; D008962:Models, Theoretical; D010545:Peroxides / Q000737:chemistry; D025341:Principal Component Analysis; D017550:Spectroscopy, Fourier Transform Infrared; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D000588:Amines; D004987:Ethers; D007616:Kaolin; D010545:Peroxides; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Chemical treatment; Chemometric tools; Etheramine; Kaolinite; Thermal treatment